The OO Judge above was equipped with de-fog and rear speaker and the speaker opening is obviously on the pass. side. So I think you'd be correct in making your car the same. It is a rare option combination, so finding one that shows whether it's the slimmer elongated vent or the usual vented rectangular one when combined w/the speaker is the key, yeah.

Tracker1.....I just saw that you said the OO Judge ha "Electric Window Defog" on the PHS....To add a little more to this subject, 1970 was the first year that the ELECTRIC window defog was available....This was the Electric Grid in the Rear Glass System...That was Rare in 1970 as it only started becoming common in the early 70's...
If this s what he PHS says than that is the style they are referring to...
Also...The SLIM grill IS an indicator of the Seat Back Mounted Motor...The was tucked back close to the seat and the plastic duct routed the Air to the grill mounted JUST BEHIND the seat..as shown in one of the first pics above...The more common rectangle grill is an indicator of the Package Tray Motor..
I will post pics of the Seat Divider system shortly....No Seat Back divider used I presume???As answers come, questions develop....Thanks...

Here is the pic of the original system in the 1969 I was referring to...

Sorry, Flipped the pic before it was uploaded...

Trying Again...Note the Speaker shown here is added on later...

----I think the 1st use of the grid electric window heater on a Pontiac was in 1969 on Grand Prix's.....Bill S

My '70 Judge Ram Air IV has the electric grid rear defroster. '70 was the first year that it was available in A Body Pontiacs.

There's a 1970 GM Factory TSB somewhere telling the dealers that their rear "defogger" blower was just that,and not intended to de-ice.
Their rear warming electric grid came out soon after and was now touted as a "defroster".